fix: resolve frontend display inconsistencies in mobile clients and preferences

- Fix error showing empty clients state: when an error occurs on initial
  load, suppress the EmptyMobileClients placeholder since the error banner
  already communicates the failure.

- Fix false empty before relay session: treat missing accountId (relay
  session not yet established) as initial loading state to show the
  skeleton instead of a misleading 'No mobile clients' message.

- Fix preference switch stale after update: use optimistic local state
  for publishAgentActivity so the switch immediately reflects the new
  value after a successful update, rather than waiting for the async
  refresh to complete.

Author: cursoragent

apps/web/src/components/clerk/MobileClientsUserProfilePage.tsx

@@ -107,7 +107,9 @@ function EmptyMobileClients() {
 export function MobileClientsUserProfilePage() {
   const devicesState = useManagedRelayDevices();
   const devices = devicesState.data ?? [];
-  const isInitialLoad = devicesState.data === null && !devicesState.error;
+  const isInitialLoad =
+    !devicesState.accountId || (devicesState.data === null && !devicesState.error);
+  const hasErrorWithoutData = devicesState.error !== null && devicesState.data === null;
 
   return (
     <div className="flex min-h-[30rem] w-full flex-col bg-background text-foreground">
@@ -149,7 +151,7 @@ export function MobileClientsUserProfilePage() {
 
         {isInitialLoad ? (
           <MobileClientsSkeleton />
-        ) : devices.length > 0 ? (
+        ) : hasErrorWithoutData ? null : devices.length > 0 ? (
           <ul className="space-y-3">
             {devices.map((device) => (
               <MobileClientRow key={device.deviceId} device={device} />

apps/web/src/components/settings/ConnectionsSettings.tsx

@@ -1586,6 +1586,14 @@ function ConfiguredCloudLinkRow({ canManageRelay }: { readonly canManageRelay: b
   const [operationError, setOperationError] = useState<string | null>(null);
   const [isUpdating, setIsUpdating] = useState(false);
   const [isUpdatingPreference, setIsUpdatingPreference] = useState(false);
+  const [optimisticPublishActivity, setOptimisticPublishActivity] = useState<boolean | null>(null);
+
+  const serverPublishActivity = primaryCloudLinkState.data?.publishAgentActivity ?? null;
+  useEffect(() => {
+    if (optimisticPublishActivity !== null && serverPublishActivity === optimisticPublishActivity) {
+      setOptimisticPublishActivity(null);
+    }
+  }, [serverPublishActivity, optimisticPublishActivity]);
 
   const reportUpdateFailure = (cause: unknown) => {
     const message = cause instanceof Error ? cause.message : "Could not update T3 Connect access.";
@@ -1689,6 +1697,7 @@ function ConfiguredCloudLinkRow({ canManageRelay }: { readonly canManageRelay: b
     }
 
     primaryCloudLinkState.refresh();
+    setOptimisticPublishActivity(enabled);
     toastManager.add({
       type: "success",
       title: enabled ? "Agent activity enabled" : "Agent activity disabled",
@@ -1734,7 +1743,11 @@ function ConfiguredCloudLinkRow({ canManageRelay }: { readonly canManageRelay: b
           control={
             <Switch
               aria-label="Publish agent activity to mobile clients"
-              checked={primaryCloudLinkState.data?.publishAgentActivity ?? false}
+              checked={
+                optimisticPublishActivity ??
+                primaryCloudLinkState.data?.publishAgentActivity ??
+                false
+              }
               disabled={
                 !canManageRelay ||
                 !isSignedIn ||